Method for acquiring logging while drilling curve sampling rate data

Abstract

The invention discloses a method for obtaining logging while drilling curve sampling rate data, and relates to the technical field of oil-gas exploration, and the method comprises the steps: extracting straight line segments and a text object based on PDF page information, and screening out transverse line segments and vertical line segments from the straight line segments; screening out a depth channel drawing vertical line segment from the vertical line segments, and screening out a depth text object located in the depth channel drawing vertical line segment from the text object; screening out a depth transverse line segment from the transverse line segments, and matching the position coordinates of the depth text object and the depth transverse line segment; substituting the depth transverse line segment and the depth text object matched with the depth transverse line segment into a preset mapping conversion relational expression, and calculating to obtain a mapping parameter value; and screening sampling rate line segments from the transverse line segments, and calculating depth data based on the sampling rate line segments and the mapping relational expression. According to the method, the logging while-drilling curve sampling rate data can be more accurately obtained from the original PDF file.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a method for obtaining sampling rate data of a logging while drilling curve. Background Art

[0002] Since offshore logging instruments record time signals, the corresponding time-depth conversion will be performed during the playback of logging data, and a PDF drawing file will be directly generated on the instrument at the acquisition end, which can display information such as sampling rate. The corresponding data of the PDF file transmitted back to the land office is a las file, which is a file format of equally spaced sampling, resulting in the original sampling rate being processed by equally spaced interpolation. Therefore, the original data sampling rate cannot be obtained from the las file, and the sampling rate information cannot be imported in the real-time logging interpretation work. The logging interpretation engineer cannot judge the validity of the real-time data based on the sampling information. Therefore, it is necessary to directly extract the corresponding curve sampling rate data from the PDF file to enhance the accuracy of the logging interpretation.

[0003] There are currently two methods for obtaining the sampling rate data needed for real-time curve logging interpretation work in offshore well logging: one commonly used method is to manually read the original PDF file directly from the land office, and then manually determine the reliability of the curve quality; the other method is to convert the PDF file into an image, and then perform pixel-level recognition through OCR to obtain the sampling information data and add it to the interpretation software for viewing. This method of obtaining data has poor accuracy and contains a large number of errors, and can only be used as a reference for qualitative judgment.

[0004] The current methods using manual readings and image OCR recognition have the following defects: ① The accuracy of sampling data acquisition is poor, which ultimately leads to too many operational steps for curve sampling quality judgment, increased logging interpretation work hours, and low efficiency; ② The quality control of key positions that need to be focused on in the logging interpretation process still needs to refer to the original PDF file for viewing.

[0005] Therefore, how to more accurately obtain the sampling rate data of the logging while drilling curve from the original PDF file is a problem that needs to be solved urgently. Summary of the invention

[0006] In order to solve the problem of poor accuracy of the sampling rate data of the logging while drilling curve obtained in the prior art, the present invention provides a method for obtaining the sampling rate data of the logging while drilling curve.

[0007] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for obtaining sampling rate data of a logging while drilling curve, comprising:

[0008] Extract straight line segments and text objects based on PDF page information, and select horizontal line segments and vertical line segments from the straight line segments;

[0009] Filter out the vertical line segments drawn by the depth channel from the vertical line segments, and filter out the depth text objects located in the vertical line segments drawn by the depth channel from the text objects;

[0010] Filter out the depth horizontal line segments from the horizontal line segments, and match the position coordinates of the depth text object and the depth horizontal line segments;

[0011] Substituting the depth horizontal line segment and the depth text object matching the depth horizontal line segment into a preset mapping conversion relationship to calculate a mapping parameter value;

[0012] The sampling rate segments are selected from the horizontal line segments, and the depth data is calculated based on the sampling rate segments and the mapping relationship.

[0013] In one embodiment, the step of extracting straight line segments based on PDF page information includes:

[0014] Use the preset graphic extraction tool to extract graphic operators from PDF pages;

[0015] Draw the endpoints of straight line segments based on graphics operators;

[0016] Filter out the starting position coordinate point and the corresponding moving position coordinate point from the endpoints of the straight line segment;

[0017] Draw a straight line segment based on the starting position coordinate point and the moving position coordinate point.

[0018] In one embodiment, the step of selecting horizontal line segments and vertical line segments from the straight line segments includes:

[0019] Extract all straight line segments with the same ordinate and different abscissa as horizontal line segments;

[0020] Extract all straight line segments with the same horizontal coordinate and different vertical coordinate as vertical line segments.

[0021] In one embodiment, the step of selecting the depth channel from the vertical line segments and drawing the vertical line segments comprises:

[0022] Select two adjacent vertical line segments with the largest distance from each other from the vertical line segments and draw the vertical line segments as the depth channel.

[0023] In one embodiment, the step of screening out the depth text objects located within the vertical line segment drawn in the depth track from the text objects comprises:

[0024] Get the minimum and maximum horizontal coordinates of the vertical line drawn in the depth channel, and get the position information of the text object;

[0025] Substitute the minimum horizontal coordinate, maximum horizontal coordinate and position information into the preset calculation formula;

[0026] Based on the calculation results, the depth text objects located within the vertical line segment drawn in the depth channel are filtered out.

[0027] In one embodiment, the step of selecting the depth horizontal line segments from the horizontal line segments comprises:

[0028] Calculate the length information of the horizontal line segment;

[0029] It is determined that a horizontal line segment having a length information greater than one quarter of the page width of the PDF page is a depth horizontal line segment.

[0030] In one embodiment, the step of filtering out the sampling rate line segments from the horizontal line segments comprises:

[0031] It is determined that a horizontal line segment whose length information is less than one quarter of the page width of the PDF page is a non-depth horizontal line segment;

[0032] Calculate the coordinate mode of the horizontal axis center coordinates of the non-depth horizontal line segment;

[0033] Determine the distance between the horizontal axis center coordinate of each non-depth horizontal line segment and the coordinate mode;

[0034] A non-depth horizontal line segment whose judgment result is that the distance is less than the preset distance difference is selected as the sampling rate segment.

[0035] In one embodiment, the step of matching the position coordinates of the depth text object and the depth horizontal line segment includes:

[0036] Get the width information of all depth horizontal line segments;

[0037] The bold horizontal line segments of the depth are screened out based on the width information, and the bold horizontal line segments of the depth are matched with the nearest depth text object.

[0038] In one embodiment, the step of substituting the depth horizontal line segment and the depth text object matching the depth horizontal line segment into a preset mapping conversion relationship to calculate the mapping parameter value includes:

[0039] Substituting multiple groups of bold horizontal depth line segments and depth text objects matching the bold horizontal depth line segments into a mapping conversion relational formula to calculate and obtain multiple groups of initial parameter values;

[0040] Get the average parameter value of multiple groups of initial parameter values, and the average parameter value is the mapping parameter value.

[0041] In one embodiment, the step of calculating the depth data based on the sampling rate line segment and the mapping relationship further includes the following steps:

[0042] Count the number of line segments of the sampling rate line segment;

[0043] Determine the matching rate between the number of line segments and the number of data points in the preset las file;

[0044] Determine the sampling rate quality of the las file based on the matching rate.

[0045] In the present invention, all the image and text data of the PDF page are obtained by directly extracting straight line segments and text objects from the pages of the original PDF file based on page information, horizontal line segments and vertical line segments are screened out from the straight line segments, and then the vertical lines drawn by the depth channel are screened out from the vertical line segments, and the text objects in the vertical lines drawn by the depth channel are used as depth text objects, depth horizontal line segments are screened out from the horizontal line segments, the depth horizontal line segments are matched with the depth text objects, so as to determine the depth data corresponding to the depth horizontal line segments, the depth horizontal line segments and the depth text objects matched with the depth horizontal line segments are substituted into a preset mapping conversion relationship to calculate the mapping parameter values, so as to obtain the mapping relationship between the depth data and the page coordinates, the sampling rate segments are screened out from the horizontal line segments, and then the sampling rate segments are mapped to the actual depth data based on the mapping relationship. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 It is a schematic diagram of a flow chart provided by the first embodiment of the present invention;

[0048] Figure 2 It is a schematic diagram of the original real-time logging while drilling data playback drawing object of the present invention;

[0049] Figure 3 It is a schematic diagram of a drawing object after the text object extraction operation of the present invention;

[0050] Figure 4 It is a schematic diagram of a drawing object after the horizontal line extraction operation of the present invention;

[0051] Figure 5 It is a schematic diagram of a drawing object after the vertical line extraction operation of the present invention;

[0052] Figure 6 It is a schematic diagram of the horizontal line segment drawing object remaining after removing the depth horizontal line segment of the present invention;

[0053] Figure 7It is a schematic diagram of a drawing object for extracting a depth horizontal line segment and matching a depth text object according to the present invention;

[0054] Figure 8 It is a schematic diagram of an operation route for automatically extracting a curve sampling rate in an original well logging playback drawing PDF file according to the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] The embodiment of the present invention provides a method for obtaining sampling rate data of a logging while drilling curve. Figure 1 , Figure 1 This is a flow chart of a first embodiment of a method for obtaining sampling rate data of a logging while drilling curve according to the present invention.

[0057] In this embodiment, the method includes steps S10 to S50:

[0058] Step S10, extracting straight line segments and text objects based on the PDF page information, and selecting horizontal line segments and vertical line segments from the straight line segments;

[0059] It should be noted that the page information includes drawing commands such as graphic operators, text content, etc.

[0060] The straight line segments and text objects are extracted from the PDF page through the extraction tool, and then the horizontal line segments and vertical line segments are selected from all the straight line segments.

[0061] Step S20, filtering out the vertical line segments drawn by the depth channel from the vertical line segments, and filtering out the depth text objects located in the vertical line segments drawn by the depth channel from the text objects;

[0062] It should be noted that, refer to Figure 2 The original data contained in the PDF page include gamma curve, resistivity curve, density and neutron curve. Each curve corresponds to multiple horizontal line segments, vertical line segments and corresponding sampling rate curves, sampling rate segments and text labels (the text is six text objects of gamma, resistivity, density, neutron, 2000 and 2010). The original data also includes depth channel. There is no grid in the depth channel, only depth data.

[0063] In order to facilitate the subsequent acquisition of depth data, the vertical line segments drawn by the depth channel are first screened out from the vertical line segments, and the depth text objects located in the vertical line segments drawn by the depth channel are screened out from the text objects. The depth text objects are digital texts. Figure 3 In the gamma curve channel, there is a "gamma" text label, in the resistivity curve channel, there is a "resistivity" text label, in the density and neutron curve channels, there are "density" and "neutron" text labels, and in the depth channel, there are "2000" and "2010" digital text labels, so you only need to determine whether the text object is a digital type. If so, keep it as the final depth text object.

[0064] Step S30, selecting the depth horizontal line segment from the horizontal line segments, and matching the position coordinates of the depth text object and the depth horizontal line segment;

[0065] It should be noted that in a PDF page, horizontal line segments include depth horizontal line segments, text mark horizontal line segments and sampling rate segments. The depth horizontal line segment is a line segment indicating a specific depth position, which usually corresponds to the actual depth value.

[0066] The depth horizontal line segments are screened out from the horizontal line segments, and the specific depth horizontal line segments are matched with the position coordinates of the depth text object.

[0067] Step S40, substituting the depth horizontal line segment and the depth text object matching the depth horizontal line segment into a preset mapping conversion relationship to calculate a mapping parameter value;

[0068] It should be noted that the mapping conversion relationship from depth coordinates to PDF file page coordinates is:

[0069] Depth=Ypage*k+b(1)

[0070] Therefore, the above mapping conversion relationship can be used to combine the vertical axis coordinates of the two groups of depth horizontal line segments and the depth values ​​of the corresponding depth text objects to directly obtain the specific values ​​of the mapping parameters k and b in the vertical axis direction.

[0071] For example, the Y coordinate of the depth line segment 1 is Ypage1, and the corresponding depth value of the depth text object 1 is Depth1. The Y coordinate of the depth line segment 2 is Ypage2, and the corresponding depth value of the depth text object 2 is Depth2. The specific parameter values ​​of k and b can be solved as follows:

[0072]

[0073] b=Depth1-Ypage1*k (3)

[0074] Step S50, selecting sampling rate segments from the horizontal line segments, and calculating depth data based on the sampling rate segments and the mapping relationship.

[0075] The sampling rate segments are selected from the horizontal line segments, the vertical axis coordinates of the sampling rate segments are obtained, and the vertical axis coordinates are substituted into the mapping conversion relationship, and then the sampling rate data is mapped into depth data, so as to complete the output of the original sampling rate data.

[0076] In the present invention, all the image and text data of the PDF page are obtained by directly extracting straight line segments and text objects from the pages of the original PDF file based on page information, horizontal line segments and vertical line segments are screened out from the straight line segments, and then the vertical lines drawn by the depth channel are screened out from the vertical line segments, and the text objects in the vertical lines drawn by the depth channel are used as depth text objects, depth horizontal line segments are screened out from the horizontal line segments, the depth horizontal line segments are matched with the depth text objects, so as to determine the depth data corresponding to the depth horizontal line segments, the depth horizontal line segments and the depth text objects matched with the depth horizontal line segments are substituted into a preset mapping conversion relationship to calculate the mapping parameter values, so as to obtain the mapping relationship between the depth data and the page coordinates, the sampling rate segments are screened out from the horizontal line segments, and then the sampling rate segments are mapped to the actual depth data based on the mapping relationship.

[0077] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the first embodiment can be referred to the above description, and will not be repeated in the following. On this basis, the step S10 of extracting straight line segments based on PDF page information also includes steps S11 to S14:

[0078] Step S11, using a preset graphic extraction tool to extract graphic operators from the PDF page;

[0079] It should be noted that graphic operators are commands used to draw graphics and images in PDF documents. They define how to draw various graphic elements on PDF pages, such as lines, rectangles, circles, Bezier curves, etc. The preset image extraction tools include Pdfpig.NET control, PDFMiner library, iText library and other tools. Pdfpig.NET is a .NET version based on PdfPig, PDFMiner library is an open source PDF parsing tool for Python, and iText library is a widely used open source Java and .NET library. All three have PDF text, image and metadata extraction functions.

[0080] Specifically, tools such as Pdfpig.NET control, PDFMiner library, and iText library are used to extract graphic operators from PDF pages.

[0081] Step S12, drawing the endpoints of the straight line segment based on the graphic operator; Step S13, selecting the starting position coordinate point and the corresponding moving position coordinate point from the endpoints of the straight line segment;

[0082] It should be noted that the graphic operators include "m", "l", "b", etc. "m" means moving the brush to the specified coordinate position, "l" means drawing a straight line segment from the current point to the specified point. The starting position coordinate point is marked with "m" and the moving position coordinate point is marked with "l".

[0083] Specifically, the endpoints of all straight line segments are drawn, and based on the characteristic that the graphic operators "m" and "l" appear in pairs to draw straight line segments, the starting position coordinate points and the corresponding moving position coordinate points of all straight line segments are screened out from all endpoints to draw them into straight line segments.

[0084] Step S14, drawing a straight line segment based on the starting position coordinate point and the moving position coordinate point.

[0085] Specifically, a straight line is drawn from each starting position coordinate point to the corresponding moving position coordinate point until all straight line segments are drawn.

[0086] Based on the first and second embodiments of the present application, in the third embodiment of the present application, the same or similar contents as those of the first or second embodiments can be referred to the above description, and will not be described in detail later. On this basis, the step S10 of selecting horizontal line segments and vertical line segments from the straight line segments also includes steps S15 to S16:

[0087] Step S15, extracting all straight line segments with the same ordinate and different abscissa as horizontal line segments;

[0088] Specifically, in the PDF page, all straight line segments with the same Y coordinate but different X coordinates are extracted as horizontal line segments. The extraction results refer to Figure 4 Except for the text objects in the depth channel, there are horizontal line segments with the same length and the same vertical coordinates in the gamma curve channel, resistivity curve channel, density curve channel, and neutron curve channel.

[0089] Optionally, the step of screening out the depth horizontal line segments from the horizontal line segments comprises the steps of:

[0090] Calculate the length information of the horizontal line segment; determine that the horizontal line segment whose length information is greater than one quarter of the page width of the PDF page is a deep horizontal line segment.

[0091] Depend on Figure 4 It can be seen that there are obviously longer horizontal line segments, and the horizontal line segments whose length information is greater than one quarter of the page width of the PDF page are deep horizontal line segments.

[0092] Step S16, extracting all straight line segments with the same horizontal coordinate and different vertical coordinate as vertical line segments.

[0093] Specifically, in the PDF page, all straight line segments with the same X coordinate but different Y coordinates are extracted as vertical line segments. The extraction results refer to Figure 5 There are vertical line segments with the same length and the same horizontal coordinates in the gamma curve, resistivity curve, density and neutron curves, and the vertical line segments at both ends of each curve are bold segments.

[0094] Optionally, the step of selecting the depth channel from the vertical line segments and drawing the vertical line segments comprises the steps of:

[0095] Select two adjacent vertical line segments with the largest spacing from the vertical line segments, draw the vertical line segments as the depth channel, and record their page horizontal coordinates XDepthMin and XDepthMax.

[0096] Depend on Figure 5 It can be seen that among all the vertical line segments, the two vertical line segments constituting the depth channel have the largest distance between them. Therefore, the vertical line segments can be drawn by selecting the two adjacent vertical line segments with the largest distance between them as the depth channel.

[0097] Based on the first, second and third embodiments of the present application, in the fourth embodiment of the present application, the same or similar contents as those of the first, second or third embodiments can be referred to the above description and will not be described in detail later. On this basis, the step S20 of selecting the deep text object located within the vertical line segment drawn in the depth channel from the text object also includes steps S21 to S23:

[0098] Step S21, obtaining the minimum horizontal coordinate and the maximum horizontal coordinate of the vertical line drawn in the depth channel, and obtaining the position information of the text object;

[0099] It should be noted that the depth track consists of two vertical line segments drawn by the depth track and text objects located within the two vertical line segments. Therefore, the depth text objects located within the vertical line segments drawn by the depth track can be screened out by determining the position information of the text objects.

[0100] Specifically, the horizontal coordinates of the vertical line segments drawn in the two depth channels are obtained, which are represented as XDepthMin and XDepthMax respectively, and the position information of each text object, the position information RectText of each text coordinate, is obtained, which is represented as RectText (X, Y, Width, Height), where X and Y represent the horizontal and vertical axis coordinates respectively, Width represents the width of the text object, and Height represents the height of the text object.

[0101] Step S22, substituting the minimum horizontal coordinate, the maximum horizontal coordinate and the position information into a preset calculation formula. Step S23, based on the calculation result, determining the text object located within the vertical line segment drawn in the depth channel.

[0102] It should be noted that the preset calculation formula is

[0103]

[0104] Xcross=(XText-XDepthMin)*(XText-XDepthMax) (5)

[0105] XText is the sum of the X coordinate of the text object and half of the width of the text object. Compare XText with the difference between XDepthMin and XDepthMax. When the calculated Xcross < 0, it means that the corresponding text object is in the depth channel. If this text object also meets the requirements of being a digital text object, it is judged to be a deep text object.

[0106] Based on the first and second embodiments and the third and fourth embodiments of the present application, in the fifth embodiment of the present application, the same or similar contents as those of the first embodiment, the second embodiment, the third embodiment, or the fourth embodiment can be referred to the above description, and will not be repeated in the following. On this basis, the step S50 of filtering out the sampling rate line segment in the horizontal line segment includes steps S51 to S54:

[0107] Step S51, determining that a horizontal line segment whose length information is less than one quarter of the page width of the PDF page is a non-depth horizontal line segment;

[0108] Specifically, refer to Figure 6 After removing the depth horizontal line segments, except for the depth channel, there are non-depth horizontal line segments that are obviously shorter than the depth horizontal line segments in the gamma curve channel, resistivity curve channel, density curve channel, and neutron curve channel. The non-depth horizontal line segments include text logo horizontal line segments and sampling rate segments. The length of the non-depth horizontal line segments is less than one-quarter of the width of the PDF page. By screening out horizontal line segments with a length less than one-quarter of the width of the PDF page as non-depth horizontal line segments.

[0109] Step S52, calculating the coordinate mode of the horizontal axis center coordinate of the non-depth horizontal line segment;

[0110] In the non-depth horizontal line segments, the X coordinates of the sampling rate segments of each channel are similar or the same, and the position of the text label horizontal line segment is significantly different from the position of the sampling rate segment. Therefore, the coordinate mode of the X coordinates of the non-depth horizontal line segments can be calculated to filter out the sampling rate segments.

[0111] Step S53, determining the distance between the horizontal axis center coordinate of each non-depth horizontal line segment and the coordinate mode; Step S54, selecting the non-depth horizontal line segment whose distance is less than a preset distance difference as the sampling rate segment.

[0112] It should be noted that, since the distance between the sampling rate line segment and the coordinate mode is very small, while the difference between the text mark horizontal line segment and the coordinate mode is obvious, the preset distance difference can be one tenth of the PDF page width or 5% of the PDF page width.

[0113] Specifically, the distance between the X coordinate of the center point of each non-depth horizontal line segment and the coordinate mode is determined, and the non-depth horizontal line segment whose distance is less than one tenth of the page width is selected as the sampling rate segment.

[0114] Based on the first and second embodiments and the third and fourth embodiments and the fifth embodiments of the present application, in the sixth embodiment of the present application, the same or similar contents as those of the first embodiment or the second embodiment or the third embodiment or the fourth embodiment or the fifth embodiment can be referred to the above description, and will not be repeated later. On this basis, the step S30 of matching the position coordinates of the depth text object and the depth horizontal line segment also includes steps S31 to S32:

[0115] Step S31, obtaining the width information of all the depth horizontal line segments; Step S32, filtering out the bold depth horizontal line segments based on the width information, and matching the bold depth horizontal line segments with the closest depth text object.

[0116] It should be noted that, in order to solve the problem of the correspondence between the extracted series of depth horizontal line segments and the depth text objects, it is impossible to directly map the depth and calculate the origin coordinates through the coordinates of the depth text objects. In particular, the positions and directions of the depth text objects in some PDF files are not uniform and have no regularity, so it is necessary to add the relevant information of the depth horizontal line segments for matching and judgment.

[0117] It should also be noted that, based on the experience of drawing logging curves, all depth horizontal line segments whose corresponding depth data is an integer are generally the specific depth values ​​marked by the depth text object. These depth horizontal line segments are bold, so the width information of the depth horizontal line segments can be added for screening. In the PDF file, the width information is marked as the "w" operator, and the comparison and judgment can be made through the width information mark corresponding to the depth horizontal line segment.

[0118] Specifically, obtain the width information identifier in the depth horizontal line segment, search for the width information of each width through the width information identifier, determine that the depth horizontal line segment with obviously larger width information is a bold depth horizontal line segment, obtain the coordinates of the bold depth horizontal line segment and the coordinates of all depth text objects, and match each bold depth horizontal line segment with the depth text object closest to it. In addition, the closest distance means that the distances between the Y coordinates and the X coordinates of the two are the closest.

[0119] Reference Figure 7 The bold depth horizontal line segments with the same Y coordinates in the gamma curve channel, depth channel, resistivity curve channel, density curve channel, and neutron curve channel are matched with the nearest integer depth text object in the depth channel.

[0120] Based on the first and second embodiments and the third and fourth embodiments and the fifth and sixth embodiments of the present application, in the seventh embodiment of the present application, the same or similar content as the first embodiment or the second embodiment or the third embodiment or the fourth embodiment or the fifth embodiment or the sixth embodiment can refer to the above introduction and will not be repeated later. On this basis, step S40 substitutes the depth horizontal line segment and the depth text object matching the depth horizontal line segment into the preset mapping conversion relationship to calculate the mapping parameter value, and also includes steps S41 to S42:

[0121] Step S41, substituting multiple groups of bold horizontal depth line segments and deep text objects matching the bold horizontal depth line segments into a mapping conversion relationship to calculate and obtain multiple groups of initial parameter values;

[0122] It should be noted that the mapping conversion relationship from depth coordinates to PDF file page coordinates is:

[0123] Depth=Y*k+b(6)

[0124] Therefore, the above linear relationship can be used to combine the two sets of depth horizontal line segment coordinates and the depth value of the depth text object to directly obtain the specific values ​​of the mapping parameters k and b in the Y direction, that is, the initial parameter values.

[0125] For example, the Y coordinate of the bold horizontal depth line segment 1 is Ypage1, and the corresponding depth value of the depth text object 1 is Depth1. The Y coordinate of the bold horizontal depth line segment 2 is Ypage2, and the corresponding depth value of the depth text object 2 is Depth2. The specific values ​​of the mapping parameters k and b are:

[0126]

[0127] b=Depth1-Ypage1*k (8)

[0128] Multiple groups of initial parameter values ​​are calculated by substituting multiple groups of bold horizontal depth line segments and depth text objects matching the bold horizontal depth line segments into a mapping conversion relationship.

[0129] Step S42, obtaining a parameter average value of multiple groups of initial parameter values, where the parameter average value is the mapping parameter value.

[0130] In order to calculate the accuracy, the parameter average of multiple groups of initial parameter values ​​is calculated, and the parameter average is used as the final mapping parameter value.

[0131] Based on the first and second embodiments and the third and fourth embodiments and the fifth and sixth embodiments and the seventh embodiments of the present application, in the eighth embodiment of the present application, the same or similar contents as the first embodiment or the second embodiment or the third embodiment or the fourth embodiment or the fifth embodiment or the sixth embodiment and the seventh embodiment can refer to the above introduction, and will not be repeated later. On this basis, after the step S50 calculates the depth data based on the sampling rate line segment and the mapping relationship, it also includes steps S51 to S53:

[0132] Step S51, counting the number of line segments of the sampling rate line segment; Step S52, determining the matching rate between the number of line segments and the number of data points in a preset las file; Step S53, determining the sampling rate quality of the las file based on the matching rate.

[0133] It should be noted that the las file is a file format for equally spaced sampling, which results in the original sampling rate being processed by equally spaced interpolation. Therefore, the original data sampling rate cannot be obtained from the las file, and the sampling rate information cannot be imported into the real-time logging interpretation work. The logging interpretation engineer cannot judge the validity of the real-time data based on the sampling information.

[0134] Specifically, according to an original sampling point corresponding to each depth point, when all depth positions within the reservoir depth range have corresponding original sampling points, the curve quality is 100%. The number of original sampling points can be determined by counting the number of sampling rate segments extracted using this method, and the number of sampling rate segments can be compared with the number of depth points in the las file to determine the curve sampling quality.

[0135] Exemplarily, for a single curve, the sampling quality Qs = the number of original sampling data points / the number of las file data points, for example, the sampling quality of the gamma curve is Qgamma, the resistivity curve is Qresistivity, etc. For multiple curves, the sampling quality Qm = (Qgamma+Qresistivity+Qdensity+Qneutron) / 4, when the calculated Qm value is 100%, it means that the curve quality of the las file is the best, when the Qm value is less than 100%, it means that the sampling rate is insufficient.

[0136] Reference Figure 8In combination with one or more of the above embodiments, a brief description of the process of extracting sampling rate data and determining curve quality is given in the present invention:

[0137] Firstly, all the graphic operators in the PDF file of the original logging curve are extracted, and the text objects are identified. The straight line segments are drawn based on the graphic operators. The vertical line objects (that is, the vertical line segments) and the horizontal line segments (that is, the horizontal line objects) are identified in the straight line segments. The depth channel is identified in the vertical line objects, and the depth text objects located in the depth channel are screened out in the text objects. In the horizontal line objects, the depth scale horizontal lines (that is, the bold depth horizontal line segments) are screened out through the width information of the horizontal line objects. The depth text objects are matched with the depth scale horizontal lines, and the depth text objects and the depth scale horizontal lines matched therewith are substituted into the mapping conversion relationship formula. The mapping relationship between the text depth of the depth text object and the page coordinates of the depth scale horizontal lines is calculated, and the corresponding mapping parameters are calculated. Finally, the curve sampling identification horizontal line objects (that is, the sampling rate segments) are screened out in the horizontal line objects, and the sampling rate segments are substituted into the mapping relationship conversion formula. The original sampling point depth (that is, the depth data) of the curve is output and the sampling quality result data of the las file is judged based on the sampling identification horizontal line objects.

[0138] Finally, it should be noted that the steps in the method of the embodiment of the present invention can be adjusted in order, combined, and deleted according to actual needs.

[0139] In addition, a person of ordinary skill in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by instructing the hardware related to the device through a program, and the program may be stored in a computer-readable storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0140] In addition, those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by functional modules in the device, which will not be elaborated herein.

[0141] What is disclosed above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiments and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for obtaining sampling rate data of logging while drilling curve, characterized in that: The method comprises: Extract straight line segments and text objects based on PDF page information, and select horizontal line segments and vertical line segments from the straight line segments; Filtering out the depth track drawing vertical line segments from the vertical line segments, and filtering out the depth text objects located in the depth track drawing vertical line segments from the text objects; Filtering out a depth horizontal line segment from the horizontal line segments, and matching the position coordinates of the depth text object with the depth horizontal line segment; Substituting the depth horizontal line segment and the depth text object matching the depth horizontal line segment into a preset mapping conversion relationship to calculate a mapping parameter value; A sampling rate segment is selected from the horizontal line segments, and depth data is calculated based on the sampling rate segment and the mapping relationship.

2. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of extracting straight line segments based on PDF page information comprises: Extracting the graphic operators of the PDF page using a preset graphic extraction tool; Drawing the endpoints of the straight line segment based on a graphics operator; Selecting the starting position coordinate point and the corresponding moving position coordinate point from the endpoints of the straight line segment; The straight line segment is drawn based on the starting position coordinate point and the moving position coordinate point.

3. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of selecting horizontal line segments and vertical line segments from the straight line segments comprises: Extract all the straight line segments with the same ordinate and different abscissa as the horizontal line segments; All the straight line segments with the same abscissa and different ordinates are extracted as the vertical line segments.

4. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of selecting the depth channel from the vertical line segments and drawing the vertical line segments comprises: Two adjacent vertical line segments with the largest spacing are selected from the vertical line segments to draw a vertical line segment for the depth track.

5. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of selecting the depth text objects located within the vertical line segment drawn in the depth track from the text objects comprises: Obtain the minimum horizontal coordinate and the maximum horizontal coordinate of the vertical line drawn on the depth channel, and obtain the position information of the text object; Substituting the minimum horizontal coordinate, the maximum horizontal coordinate and the position information into a preset calculation formula; The depth text object located within the vertical line segment drawn in the depth track is screened out based on the calculation result.

6. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of selecting the depth horizontal line segments from the horizontal line segments comprises: Calculating the length information of the horizontal line segment; The horizontal line segment whose length information is greater than one quarter of the page width of the PDF page is determined to be the depth horizontal line segment.

7. The method for obtaining sampling rate data of logging while drilling curve according to claim 6, characterized in that: The step of filtering out the sampling rate line segments from the horizontal line segments comprises: Determine that the horizontal line segment whose length information is less than one quarter of the page width of the PDF page is a non-depth horizontal line segment; Calculating the coordinate mode of the horizontal axis center coordinate of the non-depth horizontal line segment; Determine the distance between the horizontal axis center coordinate of each of the non-depth horizontal line segments and the coordinate mode; The non-depth horizontal line segment whose judgment result is that the distance is less than the preset distance difference is selected as the sampling rate segment.

8. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of matching the position coordinates of the depth text object and the depth horizontal line segment comprises: Obtaining width information of all the horizontal depth line segments; The bolded depth horizontal line segment is screened out based on the width information, and the bolded depth horizontal line segment is matched with the depth text object that is closest to the depth text object.

9. The method for obtaining sampling rate data of logging while drilling curve according to claim 8, characterized in that: The step of substituting the depth horizontal line segment and the depth text object matching the depth horizontal line segment into a preset mapping conversion relationship to calculate a mapping parameter value comprises: Substituting multiple groups of vertical axis coordinates of the bold horizontal depth line segments and depth data of the depth text object matching the bold horizontal depth line segments into the mapping conversion relationship formula to calculate and obtain multiple groups of initial parameter values; The parameter average values ​​of the multiple groups of the initial parameter values ​​are obtained, and the parameter average values ​​are the mapping parameter values.

10. The method for obtaining sampling rate data of logging while drilling curve according to claim 1, characterized in that: The step of calculating the depth data based on the sampling rate line segment and the mapping relationship also includes the following steps: Counting the number of line segments of the sampling rate line segment; Determine the matching rate between the number of line segments and the number of data points in a preset las file; The sampling rate quality of the LAS file is determined based on the matching rate.

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